Conventionally, an induction heating cooker of this type includes a top plate for carrying a cooking vessel placed thereon, a heating coil for inductively heating the cooking vessel, and an infrared sensor for detecting an infrared ray emitted from a bottom surface of the cooking vessel, and accurately adjusts temperature of the cooking vessel generally by use of the infrared sensor. The induction heating cooker determines that the cooking vessel is improperly placed when a temperature-rise value after a lapse of a certain time from the start of heating is small, and stops outputting of an inverter circuit when the cooking vessel is improperly placed (refer to, for example, PTL 1).
Another induction heating cooker of this type further includes a heat-sensitive element in addition to the above-mentioned constituents, and adjusts temperature of the cooking vessel by switching between temperature adjustment based on the infrared sensor and temperature adjustment based on the heat-sensitive element depending on presence or absence of a failure of the infrared sensor (refer to, for example, PTL 2).
Still another induction heating cooker of this type increases a control temperature value of the heat-sensitive element when an increase in the output of the infrared sensor from the start of heating becomes a predetermined value or more, in addition to the above-mentioned constituents (refer to, for example, PTL 3).
However, in the induction heating cooker configured as in PTL 1, in the case where the amount of oil stored in the cooking vessel is large, since a temperature-rise gradient of the bottom surface of the cooking vessel with passage of time during heating is relatively small, it is difficult to distinguish the case where the cooking vessel is slightly displaced from a detecting window of the infrared sensor during heating from the case where the cooking vessel storing large amount of oil is placed at a proper position. For this reason, even if the cooking vessel is placed at the proper position, it may be disadvantageously determined that the cooking vessel is improperly placed.
In the induction heating cooker configured as in PTL 2, since temperature control based on the heat-sensitive element has a lower response than temperature control based on the infrared sensor, after switching to the temperature control based on the heat-sensitive element, there is a case where safety lowers or cooking performances are deteriorated.
In the induction heating cooker configured as in PTL 3, since the control temperature value of the heat-sensitive element is low when a heating operation is performed by using still hot cooking vessel already used for cooking a deep-fried dish, heating may be unnecessarily stopped or outputted. For this reason, this induction heating cooker has a problem of inconvenience.
PTL 1: Unexamined Japanese Patent Publication No. 3-184295
PTL 2: Unexamined Japanese Patent Publication No. 2008-192581
PTL 3: International Publication 2008/120447 booklet